This invention relates to muzzle loading firearms, and more particularly to a breech plug and bolster assembly and to a method for fabricating such an assembly. Muzzle loading firearms include percussion cap or flintlock muzzle loading rifles and pistols. Although such firearms are technologically obsolete, they are still manufactured for collectors and enthusiasts who maintain and fire such weapons.
In the prior muzzle loading firearms, the firing of the powder charge to propel the projectile from the barrel generated firing forces acting against the bolster to bias it in a direction tending to displace the bolster out of the aperture in which it was threaded. The firing forces similarly acted against the breech plug to bias it in a direction tending to displace the breech plug rearwardly and out of the barrel. The threaded engagement of the breech plug and bolster has been the principal means resisting the displacement action of the firing forces. As the threads weaken with wear or with age and repeated firings, safety and proper functioning of the firearm may be adversely affected.
The firearm assembly disclosed in applicant's prior U.S. Pat. No. 4,065,866 provides a bolster design that precludes the firing forces from biasing the bolster outwardly of the aperture in which it is mounted and shields the breech plug from the firing forces tending to displace the breech plug out of the barrel. It has proven highly effective in the years of use since its introduction.
However, in manufacturing devices of this type, it is required that the barrel stock be prepared for the breech plug by facing, tapping, undercutting of thread, and chamfering in a screw machine. The breech plug is threaded and, therefore, must be cast or milled. The breech plug is then assembled to the barrel by male and female threads which have to be torqued to accomplish a gas-tight seal. A flat surface of the barrel has to be aligned with a flat surface of the breech plug while the torque is applied. A threaded bolster engages the threaded hole in the barrel and breech plug assembly, thereby necessitating a threading operation for the bolster and the tapping of the mating hole in the barrel and breech plug. The threaded assembly necessitates that the "communication" hole in the bolster (to allow the primer to ignite the main powder charge) be drilled in the bolster after it is assembled to the barrel. This is accomplished by a long drill entering the muzzle end of the barrel. Additionally, the threaded hole in the bolster which receives the nipple is also drilled and tapped after the bolster is assembled to the barrel. These several steps require relatively expensive and accurate operations.
It is an object of the present invention to provide a novel breech plug and bolster assembly in a muzzle loading firearm providing a long-lived assembly which may be readily fabricated.
It is also an object to provide such a breech plug and bolster assembly wherein the bolster extends through the breech plug and is securely engaged with both sides of the barrel to pin the breech plug in place.
Another object is to provide such a breech plug and bolster assembly wherein the parts may be press-fitted into assembly.
A further object is to provide such a breech plug and bolster assembly with relatively simple manufacturing operational steps.
A still further object is to provide such a breech plug and bolster configuration and method of assembly that allows predrilling of the bolster prior to assembly.
Yet another object is to provide such a breech plug and bolster assembly that is economical to manufacture, durable and safe in use, and refined in appearance.